Local legend has it that once Shah Jahan built the Taj Mahal, the hands of the workers were cut off. I cannot find any historical reference to this but some examples which say so
http://library.thinkquest.org/27638/tajmahal.html
Shahjahan cut off the hands of the workers after the completion of the Taj so Mahal that no one would ever be able to build such a marvelous monument again
http://www.sscnet.ucla.edu/southasia/Culture/Archit/TajM.html
It is alleged that on its completion, Shah Jahan ordered the right hand of the chief mason to be cut off so that the masterpiece could never be recreated.
and deny
http://agra-india.com/tajmahalhistoryandlegends.htm
There is no truth in the familiar tale that Shahjahan had the hands of his chief architect chopped off to prevent building him another building of Taj's reputation. Before he met his fate, this architect, it is said, was allowed to take in the last look to ensure perfection. At this moment he hammered the dome at the point, which caused leakage.
Does anyone have proper historical references? The Mughal period (1500 - 1800) was documented and studied by several Indian and Western historians and books such as this one. But I do not know if this tale is covered.